The trend today in all industries is more automation in order to achieve cost reduction, increased quality control and uniform productivity. Such trend is also true in the tire industry. In the building of tires, various strip material components are used such as the sidewall stabilizer ply, inner liner body ply, calendered fabric, and tire tread. These strip components originate at various locations and are brought to the tire production site in various packages for assembling into the completed tire. Heretofore, many of the strip components, with the exception of the tire tread, were handled in reel form for transportation between the production and assembling sites. However, more recently the tire tread has been stored and transported in reel form to achieve better handling, storage, and shipment of the tread component.
This packaging of the strip components is one of the main components of any tire manufacturing process or system. Improving the various component packaging will result in better assurance of component integrity and quality and better compatibility with the state of the art automatic process material handling and storage equipment. The specific component package is a very integral part of the system and the package must be able to satisfy the needs of the process equipment, the storer of the package, and the ultimate user of the package equipment at the tire construction site.
Heretofore, the tire tread was cut to lengths and manually handled into tread books or trays and allowed to stabilize and shrink to a theoretical proper length to go around the circumference of the tire. Relatively high cut length reject rates would result.
Others in the art have attempted to eliminate the tread handling problem by storing the tread as well as other strip components on reels, such as shown in U.S. Pat. No. 3,026,230. This patent discloses a reel having a liner spool for storing strips of rubber such as the tire tread for use in the tire making industry.
Other known art related to the present invention are disclosed in the following patents. U.S. Pat. No. 2,755,028 discloses another reel having a liner roller, a tire material roller and an auxillary roller as well as motors for driving and braking either roller together with means for conveying the tire tread material to and from the reel for winding and unwinding. U.S. Pat. No. 3,498,555 discloses another reel having a winding and unwinding box which is driven by means of hubs which engage the shafts of the liner and material spools. U.S. Pat. No. 3,012,735 shows another type of tire material winding housing which can articulate the liner drum from a horizontal to a vertical position in addition to articulatable driving means and braking means that engage the shafts of both spools. U.S. Pat. No. 4,013,177 shows a roller conveyor apparatus which supplies a coil to be inverted by an inverter conveyor device. The coil invertor of this construction is intended primarily for use in the steel industry. Another winding and unwinding device for strip material is shown in U.S. Pat. No. 3,424,394 in which the control of the unwinding movement is maintained by main shaft and positioning arms which are movable along another shaft to position and elevate a roll on the device for unwinding. U.S. Pat. No. 3,623,677 shows another device related to the tire manufacturing process which discloses an apparatus for delivering a predetermined length of selected stock to a tire building drum which includes an unwinding apparatus that applies a brake to the material spool and drives the liner spool for delivering the strip material from a reel to the tire making drum.
One main disadvantage with such prior windup and letoff reel apparatus is the high cost of such units, since such designs require the reel or material storage spool to be mounted in integral bearings in order that the rotatably mounted spools align with the auxillary equipment for loading and unloading the spools with the strip material. Such package configuration results in a higher initial per unit cost and has reduced liability and flexibility due to the complex and expensive components thereof also resulting in higher maintenance due to the abuse that the packages experience throughout their useful life.
The number of tread storage and transport packages or units used in a usual tire manufacturing system is considerably more than the components used with the packages such as the drive units for loading and unloading the packages. Thus, the high volume package cost was considerable in contrast to the other equipment used in conjunction with the package containing the storage spools. Preferably it would be desirable to keep the cost and design complexity of the large volume component of a tire making process, namely the strip packaging and storage unit, at a low cost with the more complicated and expensive equipment being the components which are used in fewer numbers such as at the load and unload station.
Another problem that is involved with loading strip material and in particular extruded tire tread material in reel form in a package, is that the tire tread is not completely aged when loaded and stored in the wound position. When stored in a usual vertical position, that is the spool axis is parallel to the floor or supporting structure, imperfections can develop in areas of the tread due to the weight of the outer layers or convolutions of rubber on the inner convolutions.
Therefore, the need has existed for an improved system for the handling of strip material and in particular for strip components used in the tire manufacturing process which enables increased automation throughout the system at a lower cost and with increased efficiency, and for improved apparatus used in such system and in particular the package or portable storage unit for moving the strip component between the various work stations and storage areas, and to an improved drive unit for loading and unloading the strip material on and off improved portable storage units.